The use of aliphatic aldehydes in fragrances is part of the mystique of our industry. Did not Ernest Beaux find a few bottles of aliphatic aldehydes on the lab shelf, smell them for the first time any perfumer had smelled them and suddenly realize that they would make the perfect theme for Chanel No, 5?

Sorry, but no, Beaux was a man of his times and made by his times. His “overdose” use of fatty aldehydes in Chanel No, 5 was more a result of the natural developments in organic chemistry and perfumery. If Beaux had not used these products as he did, some other perfumer would have done so and in a very short time. His creative use of these aldehydes was a result of their commercial availability at reasonable price levels, due to Rosenmund’s discovery of the reaction that bears his name (Figure 1).

The Rosenmund reaction reduces aliphatic fatty acids to aldehydes via their acid chlorides. The Rosenmund reaction also is typical of its time: it generates a great deal of chemical waste—including gaseous HCl, S02 and tar—and is not environmentally friendly by today's standards.